Question

The fully developed foetus gives signals for uterine contractions by secreting ________ hormones.

• A. Oxytocin and ACTH
• B. Oxytocin and corticosteroids
• C. ACTH and prostaglandins
• D. ACTH and corticosteroids

Hint:

Parturition trigger: Foetus $\rightarrow$ ACTH $\rightarrow$ Corticosteroids $\rightarrow$ Labour begins

Answer 1

The Correct Option is D

Concept: Parturition (childbirth) is initiated by hormonal signals from the fully developed foetus and placenta.
• The foetus secretes ACTH (Adrenocorticotropic hormone).
• This stimulates foetal adrenal glands to release corticosteroids.
• These hormones induce placenta to produce estrogens and prostaglandins.
• These, in turn, stimulate uterine contractions.

Step 1: Understand initiation of parturition.
The process begins with signals from the foetus.

Step 2: Identify hormones involved.
Foetus produces ACTH $\rightarrow$ stimulates corticosteroid secretion.

Step 3: Analyze options.
• (A) Oxytocin: Released from mother, not foetus
• (B) Oxytocin present: Incorrect
• (C) Prostaglandins: Produced later, not primary foetal signal
• (D) ACTH and corticosteroids: Correct

Step 4: Conclusion.
Thus, the correct hormones are ACTH and corticosteroids. Final Answer: Option (D)